Method and apparatus for filling a recess formed within a substrate surface

ABSTRACT

There is provided a method of filling one or more recesses by providing the substrate in a reaction chamber and introducing a first reactant to the substrate with a first dose, introducing a second reactant to the substrate with a second dose, wherein the first and the second doses overlap in an overlap area where the first and second reactants react and leave an initially substantially unreacted area where the first and the second areas do not overlap; introducing a third reactant to the substrate with a third dose, the third reactant reacting with the first or second reactant to form deposited material; and etching the deposited material. An apparatus for filling a recess is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 16/792,571 filed Feb. 17, 2020 titled METHOD ANDAPPARATUS FOR FILLING A RECESS FORMED WITHIN A SUBSTRATE SURFACE; whichclaims the benefit of U.S. Provisional Patent Application Ser. No.62/808,251, filed on Feb. 20, 2019, titled METHOD AND APPARATUS FORFILLING A RECESS FORMED WITHIN A SUBSTRATE SURFACE, the disclosures ofwhich are hereby incorporated by reference in their entirety.

FIELD OF DISCLOSURE

The present invention generally relates to methods and apparatus formanufacturing electronic devices. More particularly, the inventionrelates to methods and apparatus for filling one or more recesses formedwithin a surface of a substrate during the manufacturing of electronicdevices.

BACKGROUND

During manufacturing of electronic devices, such as an integratedcircuit (IC), recesses, such as gaps or trenches, can be created withinthe substrate. Filling the recesses can take a variety of forms,depending upon the specific application.

A typical trench filling process may be subjected to drawbacks,including void formation in the trench. Voids may be formed when thefilling material forms a constriction near the top of the trench beforethe trench is completely filled. Such voids may compromise deviceisolation of the devices on the integrated circuit as well as theoverall structural integrity of the IC. Unfortunately, preventing voidformation during trench fill may often place size constraints on thetrenches, which may limit device packing density of the devices.

If the trenches are filled for device isolation, a key parameter inmeasuring the effectiveness of device isolation may be the fieldthreshold voltage, that is, the voltage necessary to create a parasiticcurrent linking adjacent isolated devices. The field threshold voltagemay be influenced by a number of physical and material properties, suchas trench width, dielectric constant of the trench filling material,substrate doping, field implant dose and substrate bias duringprocessing.

Void formation may be mitigated by decreasing trench depth and/ortapering trench sidewalls so that the openings of the trench are widerat the top than at the bottom of the trench. A trade off in decreasingthe trench depth may be reducing the effectiveness of the deviceisolation, while the larger top openings of trenches with taperingsidewalls may use up additional integrated circuit real estate. Suchproblems can become increasingly problematic when attempting to reducedevice dimensions. Accordingly, improved methods and apparatus forfilling a recess may be desired.

SUMMARY

Various embodiments of the present disclosure relate to methods offilling a recess, such as a trench, within a surface of a substrate.While the ways in which various embodiments of the present disclosureaddress drawbacks of prior methods are discussed in more detail below,in general, various embodiments of the disclosure provide improvedmethods and apparatus suitable for filling recesses within a substratesurface. For example, exemplary methods and apparatus can be used toseamlessly fill high aspect ratio recesses with desired material, suchas dielectric material.

In accordance with at least one embodiment of the disclosure, a methodof filling a recess formed within a substrate surface includes the stepsof: providing the substrate in a reaction chamber, introducing a firstreactant to the substrate with a first dose on the surface of therecess, introducing a second reactant to the substrate with a seconddose on the surface of the recess, wherein the first and the seconddoses overlap in an overlap area and leave an area where the first andthe second doses do not overlap, introducing a third reactant to thesubstrate with a third dose, the third reactant reacting with the firstor second reactant in the area where the first and the second doses donot overlap, thereby depositing material, and etching the depositedmaterial within the recess. In accordance with various aspects, aconcentration of the first reactant in the overlap area differs from aconcentration of the first reactant in the area where the first and thesecond areas do not overlap. A number of deposition cycles including thesteps of introducing a first reactant to the substrate, introducing asecond reactant to the substrate, and introducing a third reactant tothe substrate can be repeated one or more times prior to the methodproceeding to the step of etching the deposited material. Further, oneor more deposition cycles in combination with the step of etching thedeposited material can be repeated a number of times to fill the recess.In accordance with further aspects, one of the first and secondreactants is introduced with a saturating dose and the other one of thefirst and second reactants is introduced with a subsaturating dose. Inaccordance with yet further examples, during the step of etching thedeposited material, an etch rate of the material can be higher in theoverlap area relative to the area where the first and the second areasdo not overlap. By having the doses of the first and second reactants,such that the reactants overlap in an overlap area in the top of therecess, the first and second reactants can react in the top of therecess to block or mitigate further reactions in the top of the recess.In an initially unreacted area in the bottom of the recess where thefirst and the second reactant did not overlap, the first or secondreactant may still react with the third reactant, thereby filling therecess from the bottom upwards.

According to a further embodiment, there is provided a semiconductorprocessing apparatus, for example, to provide an improved or at least analternative recess filling method, such as a method described herein. Inaccordance with at least one embodiment of the disclosure, asemiconductor processing apparatus includes one or more reactionchambers for accommodating a substrate comprising a surface having arecess formed therein; a first source for a first reactant in gascommunication via a first valve with one of the reaction chambers; asecond source for a second reactant in gas communication via a secondvalve with one of the reaction chambers; a third source for a thirdreactant in gas communication via a third valve with one of the reactionchambers; an etchant source in gas communication via a fourth valve withone of the reaction chambers; and a controller operably connected to thefirst, second, third, and fourth gas valves and configured andprogrammed to control: introducing the first reactant to the substratewith a first dose on the recess; introducing a second reactant to thesubstrate with a second dose on the recess, wherein the first and thesecond doses overlap in an overlap area and leave an area where thefirst and the second areas do not overlap (e.g., where a concentrationof one of the first and second doses is negligible or less than aboutone percent of the other of the first or second reactant and/or lessthan about one percent of the concentration the same reactant in theoverlap area); introducing a third reactant to the substrate with athird dose, the third reactant reacting with the first or secondreactant in the area where the first and the second areas do notoverlap, thereby depositing material; and etching the deposited materialin the recess. A deposition cycle including introducing the firstreactant, introducing a second reactant, and introducing a thirdreactant can be repeated as noted above prior to the step of etching thedeposited material. Similarly, one or more deposition cycles incombination with the step of etching the deposited material can berepeated a number of times to fill the recess.

In accordance with yet further exemplary embodiments of the disclosure,a semiconductor structure can be formed using a method and/or anapparatus as described herein.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein. These and other embodiments will become readilyapparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the figures, theinvention not being limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of exemplary embodiments of the presentdisclosure can be derived by referring to the detailed description andclaims when considered in connection with the following illustrativefigures.

FIG. 1A illustrates a schematic representation of a PEALD(plasma-enhanced atomic layer deposition) apparatus suitable for fillinga recess in accordance with at least one embodiment of the presentdisclosure.

FIG. 1B illustrates a schematic representation of a precursor supplysystem using a flow-pass system (FPS) usable in accordance with at leastone embodiment of the present disclosure.

FIG. 2 illustrates a flowchart of a method for filling a recess inaccordance with at least one embodiment of the disclosure.

FIG. 3 illustrates a flowchart of a method for filling a recess inaccordance with another embodiment of the disclosure.

FIG. 4 illustrates a structure in accordance with another embodiment ofthe disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below.

Turning now to the figures, FIG. 2 illustrates a flowchart of a method100 in accordance with at least one embodiment of the disclosure. Method100 can be used to, for example, fill one or more recesses, sometimesreferred to as gaps or features, created during manufacturing of astructure. The recesses may be less than 40 or even 20 nm wide and/ormay be more than 40, 100, 200 or even 400 nm deep. An aspect ratio ofthe recesses can range from, for example, about 5:1 to about 30:1.

As illustrated in FIG. 2, method 100 includes the steps of providing thesubstrate in a reaction chamber (step 105), introducing a first reactantto the substrate with a first dose on the surface of the recess (step110), introducing a second reactant to the substrate with a second doseon the surface of the recess (step 120), introducing a third reactant tothe substrate with a third dose, the third reactant reacting with thefirst or second reactant in the area where the first and the second dosedo not overlap, thereby depositing material (step 130), and etching thedeposited material in the recess (step 140).

Step 105 includes providing a substrate to a reaction chamber. As usedherein, a “substrate” refers to any material having a surface onto whichmaterial can be deposited. A substrate may include a bulk material suchas silicon (e.g., single crystal silicon) or may include one or morelayers overlying the bulk material. Further, the substrate may includevarious topologies, such as recesses (e.g., trenches or vias), lines,and the like formed within or on at least a portion of a layer of thesubstrate. By way of particular example, a substrate can include layersof SiN, SiOx and/or W, at least one of these layers having at least onerecess formed therein.

During step 105, the substrate may be brought to a desired temperatureusing, for example, a substrate heater and/or radiative or otherheaters. A temperature during steps 110-130 or 110-140 can range fromabout 100° C. to about 550° C. or about 250° C. to about 450° C. Apressure within the reaction chamber during such steps can be from about1 to about 9 or about 3 to about 7 Torr.

In accordance with various examples of the disclosure, by having thedoses of the first and second reactants, such that the reactants overlapin the top of the recess, the first and second reactants can react inthe top (overlap area), blocking or substantially blocking furtherreactions in the top of the recess. In the bottom of the recess, wherethe first and the second reactants did not overlap (e.g., where aconcentration of one of the reactants is significantly lower—e.g., lessthan about one percent of the other and/or less than about one percentof the concentration in the overlap area), the reactant can still reactwith the third reactant to thereby deposit material.

In accordance with examples of the disclosure, the dose of one of thefirst and the second reactants is saturating (e.g., relatively highamount or concentration and/or long pulse time), so that said one of thefirst and second reactants covers the whole or substantially the wholerecess, while the dose of the other one of the first and secondreactants is subsaturating (e.g., relatively short pulse time and/or lowconcentration/amount) to facilitate the first and second reactants onlyor substantially only overlapping in the top (overlap) area of therecess. In this context, relatively low can mean about ten, five, two,or one percent or less of a concentration and/or pulse amount or time ofone reactant compared to another reactant, and relatively high can meanthe other reactant has a concentration and/or pulse amount or time thatis about 10, 20, 50, or about 100 times greater for one reactant thanthe other.

A deposition cycle can include steps 110-130. The deposition cycle canbe repeated multiple times to fill the recess as depicted by the loop150. The deposition cycle may be repeated, for example, between about 1to 10,000 times, about 5 to 2,000 times or between about 10 and 1,000times. Any excess reactant and/or byproduct can be removed after one ormore (e.g., each) of steps 110-130 and/or 140 to circumvent directreactions between the reactants that might otherwise cause contaminationwithin the reaction chamber.

Method 100 may also be repeated partly via loop 160 if, for example, thetop of the recess is still blocking the reactants for reaction in thebottom area. Also, combinations of a complete repeat via loop 150 and apartial repeat via loop 160 may be made. In this way, the speed of therecess fill method may be increased.

As noted above, one of the first and the second reactants can beintroduced with a saturating (e.g., relatively large or long dose) andthe other one of the first and second reactants can be introduced with asubsaturating (e.g., relatively low or short dose). The reactant that isprovided with the saturating dose can penetrate deep in the recess toreach the bottom of the recess, whereas the reactant that is providedwith the subsaturating dose will not penetrate deep in the recess andstay in the area. The reaction between the first and second reactant maytherefore only or substantially only occur in the top/overlap area ofthe recess, thereby blocking or substantially blocking further reactionin the top/overlap area.

One of the first and the second reactants may be a potential growthreactant, whereas the other one of the first and second reactants maycomprise a low growth reactant, providing a relatively low growth incombination with the potential growth reactant. The reaction between thefirst and second reactants may therefore result in a relatively lowgrowth in the top/overlap area of the recess, such that the top/overlaparea may not be blocked by depositing material before the bottom of therecess is substantially filled.

One of the first and the second reactants may be introduced to coversaid corresponding one of the first and second areas, whichsubstantially covers the total surface of the one or more recesses. Theone of the first and second reactants may be the potential growthreactant providing potential growth dependent on the other reactant.

The one of the first and second reactants which is the potential growthreactant may comprise silicon. The first/second/potential growthreactant can be selected from the group consisting of silane amines,siloxane amines, silazane amines, (amino silanes, amino siloxanes, andamino silazanes). For example, the potential growth reactant maycomprise silanediamine such as N,N,N′,N′-tetraethyl silanediamine, suchas sold by Air Liquide (Paris, France) under the name ALOHA™ SAM.24.

The substantial low growth reactant may comprise one or more of He, Ne,Ar, Kr, Xe, N₂, NH₃ and N₂H₄, which may optionally be activated by a(direct or remote) plasma. Nitrogen in combination with a potentialgrowth reactant can result in a relatively low growth in the top of therecess. In some cases, it may be advantageous to provide the substantiallow growth reactant before providing the potential growth reactant.

The third reactant may comprise a high growth reactant providing arelatively high growth in combination with the potential growthreactant. The third reactant may be introduced with a relatively largedose to ensure that the bottom of the recess is reached by the thirdreactant so that the third reactant may react with the potential growthreactant in the bottom of the recess. Reaction in the top of the trenchfor the third reactant can be blocked because the first and the secondreactants may already have been reacted in the top of the recess.

The third reactant may comprise an oxidant, such as one or morereactants selected from the group consisting of water, hydrogenperoxide, molecular oxygen and ozone, which may be activated by a(direct or remote) plasma. Oxygen in combination with a silane amine(e.g., silanediamine, such as N,N,N′,N′-tetraethyl silanediamine) mayresult in a relatively high growth in the bottom of the recess. Forexample, one may provide N,N,N′,N′-tetraethyl silanediamine, N plasma,and then O plasma in a cyclic repetitive reaction to deposit material.Alternatively, one may provide N plasma, N,N,N′,N′-tetraethylsilanediamine, and then O plasma in a cyclic repetitive reaction todeposit the material.

As illustrated in FIG. 2, after at least one deposition cycle (steps110-130), the step of etching deposited material 140 is performed. Step140 can be configured, such that an etch rate of deposited material ishigher in a top (e.g., overlap) area of the recess, relative to a bottomarea (e.g., area where the doses to not overlap) of the recess. A numberof repetitions of loops 150, 160, relative to a loop 170 can bemanipulated based on, for example, the dimensions (e.g., height, width,or aspect ratio), configurations (e.g., how close together the recessesare), and/or geometry (e.g., the shape of the recess opening and/orshape of the walls of the recess) of the recesses.

In accordance with various examples of the disclosure, step 140 includesa dry etch process. An etchant used during step 140 can be activated by,for example, a direct or remote plasma unit. Exemplary etchants that canbe used include a halogen; specific examples include C_(x)F_(y), where xand y are integers (e.g., CF₄, C₂F₆, C₃F₈, or C₄F₈), CHF₃, NF₃, SF₆,Cl₂, BCl₃, HBr, and HI. Additive gasses, such as N₂, O₂, Ar, He, NO, andthe like can additionally be used to control the etching of depositedmaterial during step 140. By way of particular example, step 140 can beperformed at a substrate temperature of about 25° C. to about 550° C. orabout 100° C. to about 300° C. The pressure within the reaction chambercan be about 0.05 Torr to about 5 Torr or about 0.2 Torr to about 3Torr. And a flowrate of an etchant and/or additive can be from about 30sccm to about 3000 sccm or about 100 sccm to about 1000 sccm.

FIG. 3 illustrates a flowchart of a method 200 in accordance with atleast one embodiment of the disclosure. Method 200 is similar to method100, except method 200 includes a step 230 of introducing one of thefirst and second reactants again to the substrate before the thirdreactant. Steps 205, 210, 220, 240, and 250 can be the same or similarto steps 105-140 described above in connection with FIG. 2. Further,method 200 can include loops 260, 270 to repeat portions or all ofmethod 200.

For example, one may provide a silicon reactant, such asN,N,N′,N′-tetraethyl silanediamine, a nitrogen reactant, e.g.,comprising nitrogen plasma, and an oxygen reactant, e.g., comprising anoxygen plasma and then nitrogen plasma one or more times beforeproceeding to the step of etching deposited material (step 250). Loop260 and/or loop 270 may be repeated, for example, about 1 to 10,000times, 5 to 2,000 times or between 10 and 1,000 times. By adding step230 (e.g., doubling the nitrogen plasma steps) in the sequence, it isbetter assured that the reactants in the top have reacted and aresubstantially deactivated before the third reactant (e.g., oxygen)plasma is provided.

The third reactant may comprise an oxidant—e.g., ozone and/or hydrogenperoxide which in combination with silanediamine such asN,N,N′,N′-tetraethyl silanediamine may result in high growth. Ozone,and/or hydrogen peroxide do not need to be activated by a plasma toreact with the silanediamine to provide for relatively high growth andthat is beneficial because the energy of the plasma may be lower deep inthe recess.

The reactants for steps 210-250 can be the same or similar to thosedescribed above. Alternatively, the potential growth reactant maycomprise an organometal, e.g., an organoaluminium such astrimethylaluminium (TMA). If the potential growth reactant comprises anorganometal, e.g., an organoaluminium such as trimethylaluminium (TMA),the substantial low growth reactant may comprise ozone. Ozone incombination with trimethylaluminium may result in low growth in the topof the recess.

The third reactant may comprise hydrogen peroxide, which in combinationwith trimethylaluminium, may result in high growth in the bottom of therecess; hydrazine, which in combination with trimethylaluminium, mayresult in high growth in the bottom of the recess; and/or water, whichin combination with trimethylaluminium, may result in high growth in thebottom of the recess.

FIG. 4 illustrates a structure 400 formed in accordance with exemplarymethods (e.g., method 100 or method 200) and/or using an apparatus asdescribed herein. Structure 400 includes a substrate 402, a recess 404formed therein, and deposited material 406. Deposited material 406 canbe seamless, such that no visible void in deposited material 406 isformed.

Turning now to FIG. 1A and FIG. 1B, a semiconductor processing apparatus30 is illustrated. Semiconductor processing apparatus 30 includes one ormore reaction chambers 3 for accommodating a substrate comprising asurface having a recess formed therein; a first source 21 for a firstreactant in gas communication via a first valve 31 with one of thereaction chambers; a second source 22 for a second reactant in gascommunication via a second valve 32 with one of the reaction chambers; athird source 25 for a third reactant in gas communication via a thirdvalve 33 with one of the reaction chambers; an etchant or fourth source26 in gas communication via a fourth valve 34 with one of the reactionchambers; and a controller 27 operably connected to the first, second,third, and fourth gas valves and configured and programmed to control:introducing the first reactant to the substrate with a first dose on therecess; introducing a second reactant to the substrate with a seconddose on the recess, wherein the first and the second dose overlap in anoverlap area and leave an area where the first and the second areas donot overlap; introducing a third reactant to the substrate with a thirddose, the third reactant reacting with the first or second reactant inthe area where the first and the second areas do not overlap, therebydepositing material; and etching the deposited material in the recess.Although not illustrated, semiconductor processing apparatus 30 caninclude additional sources (e.g., for additives as described herein, forinert gasses, and the like) and additional components.

Optionally, semiconductor processing apparatus 30 is provided with aheater to activate the reactions by elevating the temperature of one ormore of the substrate, the first, second and third reactants, theetchant and/or additives. Exemplary single wafer reactors, designedspecifically to perform ALD processes, are commercially available fromASM International NV (Almere, The Netherlands) under the tradenamesPulsar®, Emerald®, Dragon® and Eagle®. Exemplary batch ALD reactors,designed specifically to perform ALD processes, are also commerciallyavailable from ASM International NV under the tradenames A400™ andA412™.

Optionally, the semiconductor processing apparatus 30 may be providedwith a radiofrequency source operably connected with the controllerconstructed and arranged to produce a plasma of the first, second orthird reactant and/or etchant and/or additive. The plasma enhancedatomic layer deposition (PEALD) may be performed in an Eagle® XP8 PEALDreactor available from ASM International NV of Almere, the Netherlandswhich apparatus comprises a plasma source to activate one or more of thereactants.

The process cycle with a plasma may be performed using semiconductorprocessing apparatus 30, desirably in conjunction with controlsprogrammed to conduct the sequences described herein, usable in at leastsome embodiments of the present disclosure. In the apparatus illustratedin FIG. 1A, by providing a pair of electrically conductive flat-plateelectrodes 4, 2 in parallel and facing each other in the interior 11(reaction zone) of reaction chamber 3, applying RF power (e.g., 13.56MHz or 27 MHz) from a power source 20 to one side, and electricallygrounding the other side 12, a plasma is excited between the electrodes.

A temperature regulator is provided in a lower stage 2 (the lowerelectrode), and a temperature of substrate 1 placed thereon can be keptat a relatively constant temperature. The upper electrode 4 serves as ashower plate as well, and reactant gas (and optionally a noble gas),precursor gasses, and etchant gas are introduced into the reactionchamber 3 through gas lines 41-44, respectively, and through the showerplate 4.

Additionally, in the reaction chamber 3, a circular duct 13 with anexhaust line 7 is provided, through which gas in the interior 11 of thereaction chamber 3 is exhausted. Additionally, a transfer chamber5—e.g., disposed below the reaction chamber 3, is provided with a sealgas line 24 to introduce seal gas into the interior 11 of the reactionchamber 3 via the interior 16 (transfer zone) of the transfer chamber 5,wherein a separation plate 14 for separating the reaction zone and thetransfer zone is provided (a gate valve through which a substrate istransferred into or from the transfer chamber 5 is omitted from thisfigure). The transfer chamber is also provided with an exhaust line 6.In some embodiments, the deposition of multi-element film and surfacetreatment are performed in the same reaction space, so that all thesteps can continuously be conducted without exposing the substrate toair or other oxygen-containing atmosphere. In some embodiments, a remoteplasma unit can be used for exciting a gas—e.g., from one or more ofsources 21, 22, 25, and/or 26.

In some embodiments, in the apparatus depicted in FIG. 1A, a system ofswitching flow of an inactive gas and flow of a precursor or reactantgas is illustrated in FIG. 1B; this system can be used to introduce theprecursor or reactant gas in pulses without substantially fluctuatingpressure of the reaction chamber. FIG. 1B illustrates a precursor supplysystem using a flow-pass system (FPS) according to an embodiment of thepresent invention (black valves indicate that the valves are closed). Asshown in (a) in FIG. 1B, when feeding a precursor to a reaction chamber(not shown), first, a carrier gas such as Ar (or He) flows through a gasline with valves b and c, and then enters a bottle (reservoir) 20. Thecarrier gas flows out from the bottle 20 while carrying a precursor gasin an amount corresponding to a vapor pressure inside the bottle 20 andflows through a gas line with valves f and e, and is then fed to thereaction chamber together with the precursor. In this case, valves a andd are closed. When feeding only the carrier gas (e.g., a noble gas) tothe reaction chamber, as shown in (b) in FIG. 1B, the carrier gas flowsthrough the gas line with the valve while bypassing the bottle 20. Inthis case, valves b, c, d, e, and f are closed.

The precursor may be provided with the aid of a carrier gas. In the caseof ALD, which is a self-limiting adsorption reaction process, a numberof deposited precursor molecules can be determined by the number ofreactive surface sites and is independent of precursor exposure aftersaturation, and a supply of the precursor is such that the reactivesurface sites are saturated thereby per cycle. A plasma for depositionmay be generated in situ, for example, in a gas that flows continuouslythroughout the deposition cycle. In other embodiments, the plasma may begenerated remotely and provided to the reaction chamber.

In some embodiments, a dual chamber reactor (two sections orcompartments for processing substrates disposed closely to each other)can be used, wherein a reactant gas and a noble gas can be suppliedthrough a shared line whereas a precursor gas is supplied throughunshared lines.

A skilled artisan will appreciate that the apparatus includes one ormore controller(s), such as controller 27, programmed or otherwiseconfigured to cause the deposition processes described elsewhere hereinto be conducted. The controller(s) can be communicated with the variouspower sources, heating systems, pumps, robotics, and gas flowcontrollers or valves of the reactor.

It is to be understood that the configurations and/or approachesdescribed herein are exemplary in nature, and that these specificembodiments or examples are not to be considered in a limiting sense,because numerous variations are possible. The specific routines ormethods described herein may represent one or more of any number ofprocessing strategies. Thus, the various acts illustrated may beperformed in the sequence illustrated, in other sequences, or omitted insome cases.

The subject matter of the present disclosure includes all novel andnonobvious combinations and sub-combinations of the various processes,systems, and configurations, and other features, functions, acts, and/orproperties disclosed herein, as well as any and all equivalents thereof.

What is claimed is:
 1. A semiconductor processing apparatus comprising:one or more reaction chambers for accommodating a substrate comprising asurface having a recess formed therein; a first source for a firstreactant in gas communication via a first valve with one of the reactionchambers; a second source for a second reactant in gas communication viaa second valve with one of the reaction chambers; a third source for athird reactant in gas communication via a third valve with one of thereaction chambers; an etchant source in gas communication via a fourthvalve with one of the reaction chambers; and a controller operablyconnected to the first, second, third, and fourth gas valves andconfigured and programmed to control: introducing the first reactant tothe substrate with a first dose on the recess; introducing a secondreactant to the substrate with a second dose on the recess, wherein thefirst and the second doses overlap in an overlap area and leave an areawhere the first and the second areas do not overlap; introducing a thirdreactant to the substrate with a third dose, the third reactant reactingwith the first or second reactant in the area where the first and thesecond areas do not overlap, thereby depositing material; and etchingthe deposited material in the recess.
 2. The semiconductor processingapparatus of claim 1, wherein the etchant comprises one or more ofC_(x)F_(y), CHF₃, NF₃, SF₆, Cl₂, BCl₃, HBr, and HI.
 3. The semiconductorprocessing apparatus of claim 1, further comprising a remote plasmabetween the etchant source and the one or more reaction chambers.